Variable condenser



Feb. 2, 1937. s COHEN 2,069,218

VAR IABLE CONDEN SER Filed Aug. 12, 1930 4 Sheets-Sheet 1 Feb. 2, 1937. s. COHEN VARIABLE CONDENSER Filed Aug. 12, 1930 4 Sheets-Sheet 2 IN VEN TOR.

ATTORNE Feb. 2, 1937. s. COHEN 2,069,213

VARIABLE CONDENSER Filed M1 12, 1930 4 Sheets-Sheet 3 IN V EN TOR.

Feb. 2, 1937. s. COHEN VARIABLE CONDENSER Filed Aug. 12, 1930 4 Sheets-Sheet 4 INVENTOR.

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Patented Feb. 2, 1937 UNITED sTATEs PATENT OFFICE VARIABLE CONDENSER Application August 12, 1930, Serial No. 474,789

7 Claims. (Cl. --41.5)

My invention relates broadly to multiple variable condensers and more particularly to a con struction of multiple variable condenser capable of quantity production and inexpensive in manufacture.

One of the objects of my invention is to provide a simplified construction of multiple variable condenser including a chassis whichmay be assembled by the keying of several parts rigidly together to form a housing for the different sections of a multiple variable condenser for mechanically protecting the parts of the condenser and electrostatically shielding one condenser from an adjacent condenser.

Another object of my invention is to provide a construction of multiple variable condenser having a rigid supporting frame with parts keyed together, with simplified means for suspending the stator plates of the condenser between opposite sides, of the frame.

Still another object of'my invention is to provide a construction of multiple variable condenser which is capable of assembly by a minimum number of operations, with the parts so simplified that production of the condensers may be carried on with minimum expenditure and by relatively unskilled labor.

A further object of my invention is to provide a construction of multiple variable condenser having means for establishing positive electrical connection with each of the sets ofsrotor plates of the condenser system for avoiding electrical losses through rotative connection to the shaft on which the several sets of rotor plates are carried.

A still further object of my invention is to provide a construction of mounting for a multiplicity of trimmer condensers with respect to the main condensers of a multiple variable condenser system, whereby accurate adjustment between the minimum and maximum capacity limits of the main condenser may be readily obtained.

Another object of my invention is to provide a mechanical system for suspending the sets of stator plates within a supporting frame structure for a multiple variable condenser, in a manner which facilitates assembly and production of the condenser.

Other and further objects of my invention reside in the method of assembly of a condenser frame in a multiple condenser system, all as will be more clearly understood from the specification hereinafter following by reference to the accompanying drawingsin which: I

Figure 1 is a plan view of the multiple variable condenser system of my invention with a portion of one of the end frames broken away and illustrated in cross-section to show the rotation of one of the connecting members with respect thereto; Fig. 2 is a side elevation of the 5 multiple variable condenser system of my inven-, tion; Fig. 3 is an end view of the multiple variable condenser looking in the direction of the arrow 3 in Fig. 2; Fig. 4 is a cross-sectional view taken on line 4-4 of Fig. 1; Fig. 5 is a side eleo vation of the condenser chassis with two of the vertically extending frame members illustrated in cross-section for the purpose of explaining the method of assembly of the condenser of my invention; Fig. 6 is a bottom plan view of the con- 5 denser structure showing the arrangement of the frame members in the condenser chassis. Fig. 7 is a fragmentary perspective view of the condenser chassis showing the connecting tongues which are provided thereon and the manner of 20 pressing the frames to receive the several sections of the condenser system; 'Fig. 8 is a perspective view of one of the end frames of the condenser chassis; Fig. 9 is a perspective view of one of the intermediate frames of the condenser chassis; Fig. 10 is an elevational view of one of the sets of stator plates employed in the condenser system of my invention; Fig. 11 is a plan view showing the manner ofmounting the stator plates in the condenser construction 30 of my invention; Fig. 12 is a plan view of one of the stator plates per se showing the notches which are provided in the edge; thereof to facilitate the mounting of the stator plates in the stator sections of the multiple variable condens- 35 er; Fig. -13 is a perspective view of one of the keying means which I provide at the edges of the stator plates for tying the plates together in positive spaced relationship; Fig. 14 is a perspective view of one of the end members by which 40 the stator plates are suspended between opposite sides of the condenser chassis; and Figs. 15 through 20 represent variousstages in the process of securing the parts of the chassis together by upsetting the ends of the tongues which pro- 45 ject through slots aligned therewith in complementary parts of the condenser frame; and Fig. 21 is a. perspective view of one of the angularly adjustable connectors used in the condenser system of my invention. 50

Referring to the drawings in detail, the cradle of the condenser shown by reference character I, comprises a bottom portion having two upstanding side portions struck therefrom. The cradle may be formed by a pressing operation 55 where the parts of the cradle are properly shaped and parts thereof cut out, as shown. The cradle I is provided with a multiplicity of laterally extending partition members 2, 3, 4, 5 and 6, which connect rigidly with the cradle by a system of mechanical joints, as shown. For example, the cradle I is provided at each thereof with projecting lugs Ia, and the end frames 2 and S are provided with corresponding apertures adapted to receive the projecting lugs. The end frame 2, for example, has been illustrated as havin apertures 2a aligned with the tongue Ia on the end of the cradle I. The frame 2 is provided with depending lug 2b, which fits into a correspondingly shaped cut out portion to in the chassis I. The end frames 2 and 6 are similarly connected with the chassis. The intermediate frames 3, 4 and 5 are constructed as illustrated more clearly in Fig. 9 where vertically extending slots 3a are cut in the partition members at spaced intervals corresponding to the Width of the cradle I.- The partition member 3 is provided with depending lugs 3b, which are adapted to enter correspondingly spaced apertures in in the lower portion of the chassis I. The chassis I is also provided with lugs Id on opposite ends thereof, which extend into correspondingly spaced out out portions 20 in' the end frames 2 and 6; The lugs which pass through the apertures in the frames are swaged to maintain the parts of the frames in rigid assembly. The process is illustrated more clearly in the series of views shown in Fig. 15 through Fig. 20. For example, in Fig. 15 Ihave illustrated the end frame view having the lug Ia of the chassis I extending through the aperture 211 therein. The end view of the lug as it projects through the aperture is more clearly shown in Fig. 16. The manner of swaging the lug Ia has been shown in Fig. 1'7. It will be seen that the lug is actually upset or outstruck in its character .by lateral and longitudinal pressure strokes against the end of the lug Ia, as shown at Ia, 5b, and I c. The end of the lug la is expanded and. serves to lock the chassis and the end frame rigidly together as a unit. This same process is followed in anchoring each of the several joints of the condenser frame.

Where the intermediate sections 3, E, and 5, join the sides of the chassis I, I dense the metal of the chassis as shown at Ie and If on each side of the partition member as it passes normal to the side of the chassis. The manner of densing the sides of the chassis adjacent each of the par tition members 3, 4 and 5, is more clearly illustrated in Fig. 2. The rotatable shaft I O of the variable condenser is journaled adjacent opposite ends in the end frames 2 and 6, as represented as 'l and B. The position of shaft I I! may be adjusted longitudinally of the chassis by means of the adjusting screw member illustrated at 9. The several sets of stator plates of the multiple variable condenser, have been indicated at I2, I3, I4 and I5, suspended between the sides of the cradle. The construction of the stator sets shown herein is particularly novel in that the suspension of the plates between the sides of the stator is greatly facilitated. The stator plates must be well insulated from the cradle at the same time that a rigidly mechanical protection is obtained. As shown in Figs. 10, Hand 12, the stator plates are provided at opposite sides thereof with indentations or cut out portions I26. and HI) and on one of the laterally extending sides thereof there are key-ways I2d and I20, formed therein. At the ends of the plates, I provide strip-like members I6 which are slotted at their edges as shown at Mia and I6b to receive the edges of the plates constituting the stator. By keying the plates together a set of stator plates is provided which is very rigid in its construction. The edges of the stator plates at each side of the keyways are swaged against to interlock the plates with the strip-like members I6 at Mia and I611. The strip-like members 30 which serve as keys to interlock the key-ways I2d and I20 are constructed as illustrated in Fig, 13 with slots 352a and 30b at each side thereof over which the edges of the stator plates are swaged or densed as shown more clearly in Fig. 10. In order to suspend the sets of stator plates in the cradle I, I provide insulated plates I1 which are secured by rivets I8 to the opposite sides of the chassis I. The insulated plates II project upwardly to a position adjacent the perforations or cut-off, portions 21 in the sides of the cradle I. The crade I is shown with the sides thereof apertured or perforated at 21 and the upper portions thereof offset at 26 in a plane out of alignment with the lower wall of the chassis or cradle I. The oifset portion of the side wall of the chassis at 26 serves as a capacity area for one side of a trimmer condenser, the opposite plate of which is shown at 22. The plate 22 is connected through resilient strip 2I to a depending tongue 20 which is supported with respect to insulated plate IT by means of screw 35. Screw 35 passes through insulated plate I1 and engages screw threaded aperture 35a in the strip-like members I6, thereby also serving as an electrical connection for the trimmer condenser to one side of the stator. The plate 22 is insulated from the capacity area 26 by means of insulation sheet 25.

An insulated washer 23 serves as a means for insulting adjusting screw 24 from the conductive plate 22 while permitting adjustment of plate :22 with respect to capacity area 26. The aperture in plate 22 through which adjusting screw 24 passes is sufficiently large to enable the adjusting screw 24 to pass freely through without establishing electrical connection therewith. The resilient connecting portion 2I- for the plate 22 tends to continuously urge plate 22 away from capacity area 26. By adjusting screw 24 the plate'22 is variably related to the capacity area 25 bringing about the proper adjustment for the capacity variation of the associated set of stator and rotor plates. Connections may be made to the sets of stator plates through the lugs 20. The rotor plates which are carried upon shaft III' have been designated generally at 3I as carried in slotted sleeve members 34 which are telescopically mounted on shaft I 0. The edges of the rotor plates are provided with a key-way in which an insulation strip 32 is disposed immediately adjacent a metallic key strip 33. This arrangement insures the positive locking of the rotor plates 3| in definite spaced relation and also provides a mechanical stop for the rotor plates at one of the extreme limits of rotation of shaft II! where tremity thereof and a yoke portion 28b on the other extremity thereof adapted to embrace the end of the bushing 34 on opposite sides of the rotatable shaft Ill. The strip 28 is formed from resilient material and has anoutstruck lug 29 therein adapted to enter any one of a multiplic-- ity of apertures 36 disposed in the end frames 2 and 6 or in the intermediate frames 3, 4 and 5. It will be seen that the connecting members 28 may be inserted into the condenser chassis to any desired angle with the bowed portion of the fork 28b embracing opposite sides of rotatable shaft l and establishing a frictional contact with the end of bushing 34 throughout the path of rotation of the rotor plates. This removable connecting strip is highly desirable in providing the shortest possible connection between the rotor plates and the associated parts of the amplification system with which the tuned condenser is used. That is, if assembly of the condenser with other parts of the amplification system is facilitated by bringlng out the connections to lugs 28a in one position of the condenser frame, the strips are shifted to meet the desired conditions. In this way some of the leads to the rotor plates may be taken out at one side of the condenser chassis while other leads to the condenser frame are taken out from the other side of the condenser frame. Theintermediate frames 3, 4 and 5 serve as electrostatic shields between the different sections of the condenser for preventing electrical coupling between' the stages of the tuning condenser.

It will be seen that the assembly of the condenser of my invention is relatively simple and does not require any considerable amount of skill for carrying out the assembly operation. I

have found the condenser system of my inventhe appended claims.

What I claim as new and desire'to secure by Letters Patent of the United States is as follows:

1. Means for establishing connection withthe individual stages of a multiple variable condenser which includes, a frame structure, a rotatable shaft member journaled in said frame structure, a set of stator plates insulatingly supported with respect to said frame structure, a sleeve carried by said shaft, a set of rotor plates supported by said sleeve'and adapted to be variably interleaved with said stator plates, a connector comprising a resilient strip forked at one end to embrace said rotatable shaft and to establish electrical connection by frictional engagement with the end of said sleeve, the frame structure adjacent said stator plates having means for supporting said connector in any one of several selected angular positions with respect to said rotatable shaft with said connector extending beyond the limits of said frame structure and parallel to the plane of said frame structure for providing a connection to said rotor plates.

2. Means for establishing connection with the individual stages of a multiple unit gang condenser which includes a chassis, a rotatable shaft journaled in said chassis, sets of stator plates insulatingly supported between the sides of said chassis, partition members extending laterally of said chassis for separating one set ofstator plates from an adjacent set of stator plates, said partition members having perforations therein disposed radially about said shaft, sleeve members carried by said rotatable shaft, sets of rotor plates supported by each of said sleeve members and adapted to be interleaved with said sets of stator plates comprising connectors for each of' chassis in spaced parallel relation to said partition member.

3. Means for establishing electrical connection with the individual stages of a multiple unit gang condenser which includes a chassis, a multiplicity of sets of stator plates insulatingly supported along said chassis, partition plates extending laterally of said chassis intermediate said sets of stator plates, a rotatable shaft journaled in certain of said partition plates, said partition plates being apertured in a plurality of different angular positions around said shaft, sets of rotor plates carried by said shaft and adapted to be interleaved with said sets of stator plates, comprising individual connectors for each of said sets of rotor plates removably positioned adjacent each of said partition plates, lugs on said connectors projectable through selected apertures in said partition plates and frictionally engaging a portion of said sets of rotor plates and a connecting lug portion extending from said connectors and projecting in spaced parallel relation with respect to said partition plate for establishing electrical connection with said rotor plates in any selected angular direction with respect to said chassis.

4. Means for establishing connection with the individual stages of a multiple variable condenser which includes a frame structure, sets of rotor and stator plates housed by said frame structure, said frame structure being perforated in a plurality of radial positions about the axes of said rotor plates which comprises a spring member including a bowed fork having a connecting lug formed on one end thereof and a projecting lug intermediate the ends thereof, said bowed fork being detachable from said frame member and being shiftable to selected angular positions withthe lug thereon passing through a selected perforation in said frame structure and a solder terminal carried by the end of said bowed fork and extending in parallel spaced relation to said frame structure for the establishment of an electrical connection with said set of rotor plates with saidconnecting lug in any selected angular position with respect to said frame structure.

5. Means for establishing connection with the individual stages of a multiple variable condenser, of the type including a frame having stator sections insulatingly supported at spaced intervals in the frame, with a. shaft journaled in said frame, and sleeve members mounted on said shaft, carrying rotor sections for interleaving relation with respect to the, stator sections, and in which electrostatic shield plates are disposed between ad jacent stator sections and project beyond the limits of the coacting rotor sections when in minimum capacity position, said electrostatic shields being apertured in a multiplicity of radial positions, comprising, bowed forks having a connecting lug portion projecting beyond the limits of the electrostatic shield plates in any selected angular position with the forked ends embracing said shaft and yieldably engaging the ends of said sleeve members, said bowed forks each having an intermediate outstruck lug thereon engageable in any one of the radially positioned apertures in said shield plates for maintaining the lug portions of said bowed forks in'a predetermined angular position with respect to said shield plates.

6. A connector and friction brake for a rotary variable condenser comprising a bifurcated strip having resilient portions extending on opposite sides of the condenser shaft and yieldably engaging on opposite faces thereof a portion of the rotary element of the condenser and the frame plate adjacent thereto, said strip having a tongue portion with an outstruck lug disposed therein and engageable in any one of a multiplicity of recesses formed in the frame plate, said tongue portion having an extension of reduced section thereon bent in a plane parallel to the plane of the frame plate and projecting in spaced relation thereto for providing a solder terminal for establishing electrical connection with the rotary element of said condenser.

7. In an electrical condenser, the combination with a stator element, of a supporting structure including a frame providing a. surface extending longitudinally of the frame along and adjacent to the stator element, a strip of insulating material mounted on and secured to said surface, means for securing said stator element to said strip, means providing a second surface on said frame spaced from the first-named surface and lying in the plane of the outer surface of said strip of insulating material, a strip of spring conducting material arranged to lie over the second-named surface, said strip of spring material being bowed outwardly away from said second-named surface, a strip of dielectric material mounted between said second-named surface and the strip of spring material, and means for gradually moving said strip of conducting material into full contact with said strip of dielectric material in the region of said second surface.

SAMUEL COHEN. 

